Do you have to preauthorise a card for incidentals or can you just pay as you go?
Yes you do. it's usually a little more than the actual charge for the room. They do that in case of incidental. but you will be credited back after your stay
Yes, any hotel worldwide pre-authorizes any credit card. If you prepaid your room using any third party agency or website they only hold I believe one hundred dollars as room security deposit, fully refundable unless day damage on the room.
hope this respond help to you.
Get an answer from Hampton Inn Miami South Beach - 17th Street staff and past guests.